He was broken twice in the third set - getting a time violation from chair umpire Evanthia Asderaki in one of them.

Nadal is trying to win the Australian Open for the second time - his first title came in 2009 - and secure the 14th major of his career, equal with Pete Sampras and three behind Roger Federer's leading total of 17. The Australian Open is the only major he has not won at least twice.

It is the seventh time in Nadal's last seven appearances at Melbourne Park that he's advanced to the quarter-finals. He didn't play the Australian Open last year due to a left knee injury and stomach virus.

Nadal will play 22-year-old Bulgarian Grigor Dimitrov on Wednesday. Dimitrov advanced to his first Grand Slam quarter-final in his 14th attempt after beating No. 11 Roberto Bautista Agut 6-3 3-6 6-2 6-4. He clinched the match by breaking Bautista Agut's serve for the fourth time.

"We all know that [Nadal] has won tons of slams," Dimitrov said. "He's been a tremendous competitor. He's Rafa. But I just want to put myself in a position to play those guys.

"We've played a couple of times on clay, but there were always little things missing. But I'm quite happy with the way I'm performing so far. So I like my chances."